Discussion about the Korg PolySix synthesizer

So, really, anyone with experience please jump right in and give some
insight because I'm near my wit's end. It makes me very nervous to
remove the processor everytime I take out klm367 to work on it.

So, I have new sockets in there for ICs 30 and 31. I have brand new
wire making every connection from IC 31 and R 17. I checked every
connection to make sure they're good.

What's happening is that nothing related to programming a sound works
or responds to a knob turn or switch switching. When I turn it on
and off it gives me a light show on the patch panel then selects a
random patch with alterations.

Why would this happen? Why after months of working fine, all of a
sudden I get this crap?

It almost beings to sound like the RAM chip went bad. I've encountered
'367s with dead RAM before. If you can, using a voltmeter check the power
pins of the RAM chip (pins 9 and 18) with the power on and then with the
power off. On, it should read around 4.5 volts. Off, it should read
around 2.5 to 3 volts, depending on battery type. I've seen where the
pins of a 5514 sram chip corrode, or worse, the corrosion enters the chip
body through the metal of one of more pins and eats the metal of the pin
away inside the chip even though the pin looks good.

Another test is to load a set of voices from a tape or wav file into the
P6, then do a verify on the same tape/wav file to see if things got
scrambled when trying to store. Other possible problems are the 4011
(IC25) that controls the write access to the ramchip, or a dead/overloaded
bus buffer (IC30/IC31).

Crow
/**/

When on, the 5514 gives me around 3.9 volts and off it reads about
1.9. Funny, though, that section looks clean and even the legs look
good (shiny metal). I only did a quick test the other night and
haven't removed 367 (again) to check for more continuity problems.

I was looking for replacements online but I mostly got a lot of links
to video-game repair. Here is a list of comparable replacements as
far as I can determine:

Toshiba 5514
Harris HM6514, National 6514, Fujitsu 6514
NEC 444, RCA 5114, Hitachi 4334

Is it safe to assume any one of these can replace the 5514?

The patch and bank section of the programming controls lock up on me
so I'm not able to test whether I can load in data.

Thanks.

--- In PolySix@yahoogroups.com, The Old Crow <oldcrow@o...> wrote:
>
> It almost beings to sound like the RAM chip went bad. I've
encountered
> '367s with dead RAM before. If you can, using a voltmeter check
the power
> pins of the RAM chip (pins 9 and 18) with the power on and then
with the
> power off. On, it should read around 4.5 volts. Off, it should
read
> around 2.5 to 3 volts, depending on battery type. I've seen where
the
> pins of a 5514 sram chip corrode, or worse, the corrosion enters
the chip
> body through the metal of one of more pins and eats the metal of
the pin
> away inside the chip even though the pin looks good.
>
> Another test is to load a set of voices from a tape or wav file
into the
> P6, then do a verify on the same tape/wav file to see if things got
> scrambled when trying to store. Other possible problems are the
4011
> (IC25) that controls the write access to the ramchip, or a
dead/overloaded
> bus buffer (IC30/IC31).
>
> Crow
> /**/

I use the HM6514 all the time for repairs and new boards alike. They
are $3 ea from Jameco.

However, if the programming controls 'lock up' it still sounds like the
CPU (IC22) is crashing due to either a bad connection or the part itself
is failing.

Crow
/**/

On Wed, 28 Jul 2004, toorglick wrote:

> When on, the 5514 gives me around 3.9 volts and off it reads about 1.9.
> Funny, though, that section looks clean and even the legs look good
> (shiny metal). I only did a quick test the other night and haven't
> removed 367 (again) to check for more continuity problems.
>
> I was looking for replacements online but I mostly got a lot of links to
> video-game repair. Here is a list of comparable replacements as far as
> I can determine:
>
> Toshiba 5514
> Harris HM6514, National 6514, Fujitsu 6514
> NEC 444, RCA 5114, Hitachi 4334
>
> Is it safe to assume any one of these can replace the 5514?
>
> The patch and bank section of the programming controls lock up on me
> so I'm not able to test whether I can load in data.
>
> Thanks.

Is it possible that if a good trace is jumped that the processor is
getting *too much* input?

>
> However, if the programming controls 'lock up' it still sounds

like the

> CPU (IC22) is crashing due to either a bad connection or the part

itself

> is failing.
>
> Crow
> /**/